Chocolate is moldable, for one thing, making the design process a little easier. Thakkar, mechanical engineering student Carlo Lindner and chemistry and neuroscience major Ben Succop started tinkering in earnest. Eventually, and just in time to bring a smile to their friend Kristine Stanner’s face, they managed to build the body of a fleet of drones out of chocolate.

On Sept. 7, Stanner’s birthday, with a Chocolove video crew looking on, they flew the drone over to her at the Duke Smart Home (a live-in laboratory and residence hall for students on the Duke campus).

The rest is Facebook history. She promptly busted off a piece of the one-of-a-kind prototype and ate it.

“Anuj is one of our student workers in the lab,” said Chip Bobbert, service manager at the Innovation Co-Lab on Duke’s West Campus, which has 3-D printers and other rapid prototyping equipment for students. “He’s an engineering student and always pushes the envelope in terms of interesting ideas.”

“I like to make quirky gifts for my friends,” Thakkar said.

The students made molds with 3-D printing to shape the chocolate fuselage. The four motors and propellers are off-the-shelf parts, not chocolate, and they were held together by a frame that runs through the center of the fuselage.

Summertime in North Carolina is not a great time to be working with chocolate.

“The first drone—chocolate was falling from the sky,” Thakkar said. “It was sort of dripping in flight.”

Their early prototyping was accomplished with cheap, grocery-store chocolate, which unmolded well and gave them reasonable enough results that they were able to make a demonstration video on a smart phone and pitch the idea to Chocolove, a Boulder, Colorado, maker of all-natural and organic chocolates which sells products on the Duke campus in Durham, North Carolina.

Chocolove enthusiastically said yes, and provided high-quality dark chocolate in quantity to the team.

More testing ensued, with the team spending long, chocolate-coated days at Duke maker spaces the Co-Lab and The Foundry. The higher-quality chocolate is more brittle than the cheap stuff, so the team had to tinker a bit, first with plastic embedded in the fuselage, and then with strands of sweet vermicelli that they embedded to give the airframe a little more resilience and flex.

They crashed. A lot. The frame always held, but the fuselage had a tendency to fracture or tear, which may be why real airplanes aren’t made of chocolate. The final design ended up being about 200 grams of chocolate.

Thakkar said the students don’t have any ambitions to make their idea into a company or anything. In fact, truth be told, he’s kind of off chocolate altogether.

“I got tired of chocolate in the first day of prototyping,” Thakkar said.

It seems there was “a bucket” of product left over on that first day and the college men felt it couldn’t go to waste.